Elevator systems typically include a car that moves along guiderails within a hoistway between different levels in a building. A variety of machine configurations are used to move the car as desired. Various braking arrangements are used to maintain the elevator car at a desired landing.
Another feature typical of elevator systems is a safety braking arrangement. A governor device typically detects an overspeed condition and activates a safety braking device that is mounted on an elevator car or counterweight, for example. A safety braking device typically applies a braking force to the guiderail to decelerate the car or counterweight and bring it to a stop. One example arrangement is shown in U.S. Pat. No. 4,538,706. As shown in that document, a brake pad is forced against a surface of the guiderail during a brake application.
One attempt at avoiding applying a braking force to the guiderail surface is shown in the published application WO 2004/033354. In that document, brake pads apply a braking force to the sides of rollers that are disposed on opposite sides of the guiderail.